JP4787863B2 - Remote meter reading system - Google Patents

Description

  The present invention relates to a remote meter-reading system for remotely metering power usage mainly in an apartment building, office building, or commercial building.

  Conventionally, when each tenant in an apartment building, office building, or commercial building is a consumer, it has been placed in the cordless handset attached to the electricity meter and in the electrical room of the housing complex, office building, or commercial building. The main unit communicates with the main unit via power line carrier communication, and the meter reading data obtained by each consumer's watt-hour meter (that is, the measured data by the watt-hour meter, in this case the power consumption) A technique has been proposed that is acquired from a slave unit and collects meter reading data in the master unit (see, for example, Patent Document 1). According to Patent Document 1, the master unit is connected to a power company totaling device via a communication network such as a telephone network, and acquires meter reading data from the slave unit in response to a meter reading request from the totaling device. Remote meter reading is made possible by transmitting to the counting device or acquiring meter reading data from the slave unit and transmitting it to the counting device at predetermined intervals.

  In the above-described technology, since the master unit performs communication by power line carrier communication between the master unit and the slave unit and the master unit collects meter reading data from the slave units, the power line supplying power to each consumer is connected to the master unit. By using it as a communication path between the machine and the handset, it is possible to save construction and materials. Moreover, since the meter reading can be performed remotely, it is possible to save labor and prevent reading errors in the meter reading data as compared with the case where the meter reader visually checks the power consumption by checking the watt hour meter. .

  By the way, in the technology described in Patent Document 1, a plurality of step-down transformers (transformers) are connected to a trunk line (intake line) in a building where a customer enters, thereby branching the distribution system into a plurality of parts. Power is supplied to customers from the secondary power line (distribution line). Therefore, it is possible to divide the power distribution system for each floor in the building.

  As shown in FIG. 10, when the power distribution system is branched into a plurality of power lines Lb, in order for the base unit 1 to communicate with the handset 2, any one power line Lb is connected to the base unit 1. It is conceivable that a communication signal is exchanged between the other power line Lb and the base unit 1 via the step-down transformer Tr and the trunk line Lt. However, if the communication signal passes through the step-down transformer Tr, the communication signal is greatly attenuated. The problem is that the quality deteriorates.

Therefore, Patent Document 1 employs a configuration in which a coupler 3 (an inter-transformer signal coupler) that allows communication signals to pass between different power lines Lb is used. One end of the coupler 3 is connected to each power line Lb, and the other end is connected to one set of power lines Lb. Therefore, by connecting the parent device 1 to the power line Lb, communication signals can be exchanged with all the power lines Lb with relatively high communication quality.
JP 2006-180021 A

  By the way, since one master unit 1 communicates with a plurality of slave units 2, if a request for acquiring meter reading data is made to a large number of slave units 2 at the same time, there is a high probability that congestion will occur and a communication error will occur. Problem arises. In addition, if a retransmission process is performed when a communication error occurs, there may be a variation in the time interval for acquiring meter reading data for one slave unit 2.

  On the other hand, when an electric power company determines an electricity bill, for example, meter reading data every 30 minutes may be required. If the meter reading data every 30 minutes is stored in the slave unit 2, even if the time difference notified from each slave unit 2 to the master unit 1 is 30 minutes or more, each slave unit 2 has the same time every 30 minutes. Although the meter reading data can be notified to the master unit 1, since the communication speed between the master unit 1 and the slave unit 2 is slow and the communication frequency cannot be increased, for example, about three meter reading data can be sent to the master unit 1. It is necessary to transfer to.

  However, if communication errors occur frequently as described above and the time required for retransmission processing increases, meter reading data cannot be sent even if all the time is allocated to retransmission, and the reliability of the system decreases.

  The present invention has been made in view of the above-described reasons, and the object thereof is to reduce the frequency of occurrence of communication errors, and thus to reduce the frequency of occurrence of retransmission processing, resulting in measurement data. An object of the present invention is to provide a highly reliable remote meter-reading system that can be acquired by a master unit without missing the error.

  According to the first aspect of the present invention, communication including a power line between a plurality of slave units that are provided for each power measurement device that measures power used by a consumer and that respectively obtains measurement data by the power measurement device, and the slave units The measurement data acquired by the parent device by communicating with the parent device that communicates with the power line carrier communication through the road and communicating with the parent device through the communication path including the wide area information communication network. A host management device that collects data, and a master unit that periodically acquires measurement data from a slave unit at a slot interval that is a specified time, and a master unit that acquires measurement data acquired from the slave unit It is characterized by comprising meter reading value notifying means for notifying the management apparatus and slot control means for variably determining the slot interval according to the communication conditions with the slave unit.

  According to a second aspect of the invention, in the first aspect of the invention, the slave unit is capable of multi-hop communication, and the slot control means sets the maximum number of hops in the slave unit provided under the management of the master unit. The slot interval is defined in association with each other.

  According to a third aspect of the invention, in the first aspect of the invention, the slave unit is capable of multi-hop communication, and the slot control means is an average value of the number of hops in the slave unit provided under the management of the master unit. It is characterized in that the slot interval is defined in association with.

  According to a fourth aspect of the invention, in the first aspect of the invention, the slave unit is capable of multi-hop communication, and the slot control means determines the number of individual hops in the slave unit provided under the management of the master unit. The slot interval is defined in association with each other.

  According to a fifth aspect of the present invention, in the first aspect of the invention, the slot control means defines the slot interval according to the success or failure of communication during communication with the slave unit provided under the management of the master unit, and the communication is successful. It is sometimes characterized by using a shorter slot interval than when it fails.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects of the present invention, a plurality of the master units are provided, and the slot control means sets the slot interval of each master unit to be longer as the number of master units increases. It is characterized by doing.

  According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the plurality of master units are provided, and the slot control means circulates measurement data from the slave units managed by each master unit. In this case, the start times are different from each other.

  In the invention of claim 8, in the invention of any one of claims 1 to 7, when the master unit fails to acquire measurement data from the slave unit, the master unit It is characterized by comprising backup meter-reading means for individually acquiring measurement data of the slave unit through the master unit after communication with the slave unit is enabled.

  According to a ninth aspect of the present invention, in any one of the first to eighth aspects, the master unit includes a master clock unit for measuring a reference date and time, and a master clock when performing a measurement data acquisition request to the slave unit. Date and time notifying means for notifying the child device of the date and time being measured by the means, and the child device is a slave clock means for timing the date and time and a slave clock means at the date and time of the master clock means received from the parent device. And a date and time correcting means for adjusting the date and time to be counted.

  According to a tenth aspect of the present invention, in the invention according to any one of the first to eighth aspects, the master unit has a master clock means for measuring a reference date and time, and a date and time that the master clock means is counting to the slave unit. A slave clock means for timing the date and time, and a date correction means for adjusting the date and time counted by the slave clock means to the date and time counted by the master clock means received from the master machine. It is characterized by providing.

  In the invention of claim 11, in the invention of claim 9 or 10, when the slave unit has a time difference between the date and time measured by the master clock means and the date and time measured by the slave clock means exceeds a specified time. And a slave unit processing means for stopping the operation of the slave unit.

  According to a twelfth aspect of the invention, in the ninth or tenth aspect of the invention, the slave unit has a time difference between a date and time measured by the master clock means and a date and time measured by the slave clock means exceeding a specified time. And a slave unit processing means for adding time lag information to the measurement data of the slave unit.

  According to a thirteenth aspect of the present invention, in any one of the first to twelfth aspects, the parent device estimates a delay time until a measurement data acquisition request reaches the child device; and And a date and time adjusting means for adjusting the date and time notified to the slave by the date and time notifying means by the delay time estimated by the delay time estimating means.

  According to a fourteenth aspect of the present invention, in the invention according to any one of the first to thirteenth aspects, when an event occurs in at least one of the power measuring device and the slave unit, the slave unit measures event information indicating the occurrence of the event. An event notification means to be added to the data is provided.

  According to the configuration of the first aspect of the present invention, since the master unit periodically acquires measurement data from the slave unit at a slot interval that is a specified time, congestion occurs even when there are a large number of slave units. Measurement data can be acquired from each slave unit. In other words, since the frequency of occurrence of communication errors can be reduced, the frequency of occurrence of retransmission processing can be reduced, and as a result, measurement data can be acquired without omission and the reliability of the remote meter reading system can be improved. .

  In addition, since the slot interval is variably determined according to the communication conditions with the slave unit, the slot is set so that the incidence of communication errors due to an increase in traffic does not increase according to the number of master units or slave units. The interval can be set appropriately. In addition, it is possible to systematically set a time schedule by which the master unit requests each slave unit to acquire measurement data according to the slot interval.

  According to the configuration of the invention of claim 2, since the slave unit can perform multi-hop communication and the slot interval is defined by the maximum number of hops of the slave unit provided under the control of the master unit, The slot interval can be defined assuming that the machine takes the longest time to acquire measurement data from the slave unit, and the slot interval can be set to a fixed time for all slave units In addition, it is possible to construct a remote meter reading system in which congestion is unlikely to occur.

  According to the configuration of the invention of claim 3, multi-hop communication is possible in the slave unit, and the slot interval is defined by the average value of the number of hops of the slave unit provided under the management of the master unit. When a master unit acquires measurement data from a slave unit, a slave unit with more hops than the average value may cause congestion with other slave units, but the frequency of congestion should be relatively low. Can do. That is, it is possible to provide a remote meter reading system in which the slot interval is set to a fixed time and the slot interval can be set shorter than when the slot interval is defined with the maximum number of hops, and the congestion is less likely to occur.

  According to the configuration of the invention of claim 4, multi-hop communication is possible in the slave unit, and the slot interval is set in correspondence with the number of individual hops of the slave unit provided under the management of the master unit. Therefore, by specifying the slot interval individually for each slave unit, the master unit avoids congestion with other slave units and prevents the occurrence of communication errors, and between the master unit and slave units. It becomes possible to strictly manage the bandwidth usage rate of the transmission path.

  According to the configuration of the fifth aspect of the invention, the slot interval is defined by the success or failure of communication during communication with a child device provided under the management of the parent device, and the slot interval is made shorter than the failure time when communication is successful. In an environment where the communication success rate is low, such as in a noisy environment, by increasing the slot interval, the noise band is added to the band used for communication between the master and slave units in the transmission path. In this way, the slot interval is set, and the success rate of communication can be improved.

  According to the configuration of the invention of claim 6, since the slot interval becomes longer as the number of parent devices increases, the traffic to one parent device decreases as the number of parent devices increases, and as a result, a plurality of It is possible to suppress an increase in the amount of communication per unit time in the entire system including a single master unit.

  According to the configuration of the invention of claim 7, since the start times when a plurality of master units acquire measurement data from the slave units are different from each other, each master unit is controlled by each managed slave unit. Congestion can be avoided when obtaining measurement data.

  According to the configuration of the eighth aspect of the invention, when the master unit fails to receive the measurement data from the slave unit, the upper management device is individually connected from the slave unit after the master unit becomes communicable with the slave unit. Measurement data is acquired. In general, if the master unit fails to receive measurement data from the slave unit, noise may exist and the communication path environment may have deteriorated. Although there is a high possibility that data reception will fail, acquiring measurement data after confirming that communication is possible increases the possibility of acquiring measurement data from the slave unit. In addition, even if the master unit fails to acquire measurement data from the slave unit, the host management device acquires the measurement data individually from the slave unit, so there is no need for the master unit to retransmit the measurement data to the slave unit. The time at which the master unit acquires measurement data from other slave units is not affected. That is, the time at which the master unit acquires measurement data from the slave unit can be systematically performed at slot intervals.

  According to the configuration of the ninth aspect of the invention, in order to set the date and time of the slave clock means provided in the slave unit to the date and time that the master clock means provided in the master unit is timed, a measurement data acquisition request is made to the slave unit. At this time, since the slave device is notified of the date and time being measured by the master clock means, it is not necessary to separately communicate for time adjustment, and the increase in traffic can be suppressed.

  According to the structure of the tenth aspect of the present invention, when the date and time of the slave clock means provided in the slave unit is adjusted to the date and time that the master clock means provided in the master unit is timed, the date and time that the master clock means is timed. Since the slave unit is periodically notified, occurrence of a time lag in the slave unit can be suppressed. That is, it becomes possible to acquire highly reliable measurement data with respect to time.

  According to the configuration of the invention of claim 11, when there is a significant time lag exceeding the specified time in the date and time being measured by the slave unit, the charging of the slave unit is stopped by stopping the operation of the slave unit. Can be prevented.

  According to the configuration of the twelfth aspect of the present invention, when there is a significant time lag exceeding the specified time in the date and time counted by the slave unit, the time lag information is added to the measurement data, so that it is not subject to billing. By indicating that it is information, it is possible to prevent charging based on erroneous measurement data.

  According to the configuration of the thirteenth aspect of the invention, the delay time until the measurement data acquisition request reaches the slave unit from the master unit is estimated, and the master unit notifies the slave unit of the date and time for time adjustment. Since the delay time estimated at the time is adjusted, when the time of the master clock means and the slave clock means is set, the time corresponding to the delay time is measured between the date and time measured by the master clock means and the date and time counted by the slave clock means. It is possible to prevent a date / time shift from occurring.

  According to the configuration of the invention of claim 14, when an event occurs in the slave unit or the power measuring device, event information indicating the occurrence of the event is added to the measurement data. Can be notified. The event information notified to the parent device can be grasped by the host management device as necessary. Moreover, if the backup meter-reading means of Claim 8 is used, even if the event information from a subunit | mobile_unit has not reached | attained the main | base station, it becomes possible to make a high-order management apparatus grasp | ascertain event information. Note that event information occurs when, for example, the time difference between the master clock means and the slave clock means exceeds a specified time, the power measuring device is replaced, or power is restored from a power failure. And the case where the switchgear (described in the embodiment) is operated.

  This embodiment assumes a case where a plurality of power measuring devices are arranged in one building such as an apartment house, an office building, or a commercial building. In this type of building, as shown in FIG. 2, a plurality of power lines (100V / 200V low-voltage lines) Lb branched from a trunk line (6600V medium-high voltage line) Lt to which commercial power is supplied are wired. A step-down transformer Tr is provided at a branch point between the main line Lt and each power line Lb. The step-down transformer Tr steps down the voltage of the trunk line Lt to 100 V / 200 V (single-phase three lines and the voltage line is 200 V), and has a capacity of about 20 to 200 kVA, for example. In FIG. 2, the power line Lb on the secondary side of the step-down transformer Tr is described by two lines, but actually, the secondary side of the step-down transformer Tr is a single-phase three-line. Two lines shown in FIG. 2 indicate lines of voltage poles in the power line Lb.

  In the present embodiment, a case will be described as an example where a plurality of step-down transformers Tr are provided in an apartment house and branched from a power line Lb connected to the secondary side of the step-down transformer Tr to supply each dwelling unit as a consumer. In order to charge an electric bill for each dwelling unit, each dwelling unit is provided with a power measuring device 4. As the power measuring device 4, an electronic watt hour meter is used instead of the conventional integrating watt meter. The power measuring device 4 measures instantaneous power and measures the amount of power for each time zone by integrating the instantaneous power. Therefore, for example, it is possible to individually measure the amount of power used in time zones with different unit prices such as daytime and nighttime.

  By the way, since this invention aims at measuring the amount of electric power used in each dwelling unit remotely, it is necessary to transmit the measurement data measured with the electric power measurement apparatus 4 by communication. Here, communication by power line carrier communication (hereinafter abbreviated as “PLC”, PLC = Power Line Communication) is performed using a power line Lb in a part of a communication path for transmitting measurement data obtained by the power measuring device 4. For the communication signal, for example, a high-frequency signal of 10 to 450 kHz is used.

  The measurement data of the power measurement device 4 provided in each dwelling unit is collected in the parent device 1 in units of buildings, for example. The base unit 1 communicates with a host management device 6 such as a computer server managed by an electric power company through a wide area information communication network NT such as the Internet. Accordingly, the upper management apparatus 6 can individually acquire the amount of power used in each dwelling unit.

  In order to connect the master unit 1 to the wide area information communication network NT, it is interposed between the local information communication network including the master unit 1 and the wide area information communication network NT, and between the master unit 1 and the upper management apparatus 6 A modem 5 is provided as a communication device that enables communication. The wide-area information communication network NT is a broadband communication network such as optical communication. When performing optical communication, an ONU (Optical Network Unit) is used as the modem 5. The modem 5 is provided with a LAN connection port connected to the local information communication network and a WAN connection port connected to the wide area information communication network NT.

  In order to transmit the measurement data of the power measurement device 4 provided in each dwelling unit to the parent device 1, each power measurement device 4 is provided with a child device 2 that communicates with the parent device 1. Although the subunit | mobile_unit 2 can be provided separately from the electric power measurement apparatus 4, in this embodiment, as shown in FIG. 3, the electric power measurement apparatus 4 and the subunit | mobile_unit 2 are accommodated in the one housing 40. FIG. Thus, the power supply management device 10 is configured. The power supply management device 10 includes one power measuring device 4 and one slave unit 2, and further includes an opening / closing device 9 that opens and closes an electric path from the power line Lb to the power line in each dwelling unit. The subunit | mobile_unit 2, the electric power measurement apparatus 4, and the opening / closing apparatus 9 can be attached or detached with respect to the housing 40, and can be replaced | exchanged as needed. In addition, since it is necessary for the master unit 1 to grasp the amount of power used for each dwelling unit, individual slave unit identification information (address and customer number) is set for each slave unit 2. Each slave unit 2 is identified by the slave unit identification information.

  The subunit | mobile_unit 2 is connected to each power line Lb, and since it normally supplies electric power to several dwelling units from one set (single-phase three-wire) power line Lb, several subunit | mobile_unit 2 is connected to one set of power line Lb. The Here, when the parent device 1 acquires the accumulated power amount from the child device 2, the parent device 1 polls each child device 2 at an appropriate cycle, whereby the accumulated power stored in each child device 2 is stored. Get the quantity. For example, the subunit | mobile_unit 2 hold | maintains the integrated value for every 30 minutes with respect to the measurement data which the electric power measurement apparatus 4 measured in association with time, and in order to acquire measurement data in the main | base station 1, it is a fixed period of 30 minutes or more. Regular meter reading is performed by polling (for example, selecting from 48 minutes, 72 minutes, 90 minutes, etc.). It will be described later that the slave unit 2 acquires and stores the integrated power amount from the power measuring device 4.

  In this embodiment, instead of providing a large number of communication connection ports in the base unit 1, the coupler 3 is provided by one less than the number of systems of the power line Lb. The coupler 3 has three connection ports 31 to 33, one connection port 31 of the coupler 3 is connected to the power line Lb, and the remaining two connection ports 32 and 33 are connected to the other coupler 3. Or connected to the base unit 1. Between the connection port 31 connected to the power line Lb and the other two connection ports 32 and 33, the passage of power is blocked and only the communication signal used for power line carrier communication can pass. Further, the two connection ports 32 and 33 that are not connected to the power line Lb are directly connected to each other, and communication signals can be transmitted between the connection ports 32 and 33.

  Therefore, when one connection port 31 of the coupler 3 is connected to the power line Lb and the couplers 3 are connected using the remaining two connection ports 32 and 33, a communication signal is transmitted on the same power line Lb. Of course, communication signals can be transmitted between the different power lines Lb via the coupler 3. That is, by connecting any one of the couplers 3 to the master unit 1, the master unit 1 is connected to all the power lines Lb to which the couplers 3 are connected by providing only one connection port 34. Communication signals can be exchanged with the handset 2 that is present.

  In addition to the signal connection port 34, the base unit 1 also has a power reception connection port 35. The power receiving connection port 35 is connected to any one of the power lines Lb without going through the coupler 3. That is, the coupler 3 is not connected to the power line Lb. The power receiving connection port 35 is used for receiving power from the power line Lb, and is also used for transmitting and receiving communication signals to and from the handset 2 connected to the power line Lb. The subunit | mobile_unit 2 receives electric power from the power line Lb.

  By the way, in this embodiment, the breaker 7 is inserted between each power line Lb and each coupler 3, respectively. Similarly, a breaker 7 is inserted between the power receiving connection port 35 and the power line Lb in the base unit 1. Each breaker 7 is desirably two-pole, and by providing the breaker 7 for each power line Lb, the master unit 1 and the coupler 3 are individually separated from the power line Lb without stopping power supply to each dwelling unit. Maintenance and inspection work can be performed. A single-pole or two-pole switch can be used instead of the breaker 7. In the present embodiment, by using the breaker 7, when an abnormal current flows through the base unit 1 or the coupler 3, the path of the abnormal current can be blocked so that the power source side is not affected.

  As described above, the power measurement device 4 measures the amount of power used in each dwelling unit, and the slave unit 2 acquires measurement data (integrated power amount) from each power measurement device 4. Distributed in the building. On the other hand, the master unit 1 is arranged at one place of the building in order to collect measurement data acquired by each slave unit 2. Specifically, the main unit 1 is stored in a storage box together with the coupler 3 and the breaker 7, and the storage box is disposed in an EPS (Electric Pipe Shaft) as an electrical room that stores the trunk line Lt and the step-down transformer Tr in the building. Is done.

  As shown in FIG. 3, the housing 40 of the power supply management device 10 includes a mounting base 41 that detachably mounts the slave unit 2, the power measuring device 4, and the opening / closing device 9, and a glass transparent cover that covers the mounting base 41. 42. A terminal block 41 a is provided below the mounting base 41, and the front surface of the terminal block 41 a is covered with a lid plate 43. On the terminal block 41a, a terminal (three on the left side in FIG. 3A) to which the power line Lb is connected and a terminal (three on the right side in FIG. 3A) for connecting power supply lines for supplying power to each dwelling unit Is provided.

  A socket portion 41b for detachably mounting three units of the slave unit 2, the power measuring device 4, and the opening / closing device 9 is formed on the top of the mounting base 41. The socket portion 41b is formed with a plurality of insertion ports 44a and 44b into which flat terminal pieces (not shown) projecting from the respective units are inserted. Each unit is formed with substantially the same dimensions, and is arranged in three upper and lower stages. The lower stage is the switching device 9, the middle stage is the power measuring device 4, and the upper stage is the slave unit 2. Further, as will be described below for the slave unit 2, each unit is fixed to the mounting base 41 using mounting screws.

  The switchgear 9 has a built-in relay and is connected to the slave unit 2 via a cable (not shown), and receives instructions from the master unit 1 through the slave unit 2 or receives instructions from the slave unit 2 itself. The electric circuit between the power line Lb and the power line is opened and closed. The instruction content from the parent device 1 to the child device 2 is notified from the upper management device 6 to the parent device 1. Accordingly, it is possible to manage the start and stop of power supply to each consumer (dwelling unit) in the power company that manages the upper management device 6.

  The power measuring device 4 is connected to the insertion port 44a which is a voltage terminal and the insertion port 44b which is a current terminal, and detects the line voltage of the power line Lb and the passing current between the power line Lb and the power supply line, and detects them. Instantaneous power is calculated from voltage and current. Furthermore, the power measuring device 4 has a built-in power amount measuring circuit that can integrate the instantaneous power and obtain the integrated power amount.

  An optical communication interface (not shown) using infrared rays as a transmission medium is provided on the front and upper surfaces of the body of the power measuring device 4. The optical communication interface is provided to notify an external device every predetermined time (for example, 3 seconds) that defines the integrated power amount measured by the power measuring device 4. The front optical communication interface is used for maintenance and the like, and the upper optical communication interface is used to notify the slave unit 2 of the integrated power amount.

  An optical communication interface opposite to the optical communication interface provided in the power measuring device 4 is provided on the lower surface of the housing of the slave unit 2. In the subunit | mobile_unit 2, integrated electric energy is received by infrared communication from the electric power measurement apparatus 4 through an optical communication interface, and the integrated electric energy for every predetermined time is memorize | stored. The stored accumulated power amount is transmitted to the main unit 1. The accumulated power amount of each consumer (dwelling unit) transmitted to the base unit 1 is transmitted to the upper management device 6 managed by the power company. Therefore, the electric power company can know the amount of electric power used by each customer without checking the watt hour meter by the meter reader.

  On the front surface of the housing of the slave unit 2, a notification lamp for notifying the occurrence of an abnormality and an optical communication interface including an IrDA port are provided. This optical communication interface is used for initial setting, maintenance, confirmation of the accumulated power amount (meter reading data) stored in the slave unit 2, time adjustment of the internal clock of the slave unit 2, and the like. That is, since the optical communication interface is provided, the above-described operation can be performed without contact without removing the cover 42. In order to use this optical communication interface, a maintenance terminal provided separately is used.

  Below, the function of the main | base station 1, the subunit | mobile_unit 2, the electric power measurement apparatus 4, and the high-order management apparatus 6 is demonstrated in detail. The master unit 1 and the slave unit 2 are built-in devices including a microcomputer, and execute a program for performing the operation described below.

  The subunit | mobile_unit identification information (NodeID) is provided to the subunit | mobile_unit 2, and individual measurement identification information (instrument ID) is similarly provided to the electric power measurement apparatus 4 similarly.

  The slave unit identification information is registered in the master unit 1 for the number of slave units 2 managed by the master unit 1 (for example, 180 units). In setting the slave unit identification information in the slave unit 2, the slave units 2 are operated one by one, and the slave unit identification information is received for each slave unit 2 that has been confirmed to be activated. The master unit 1 assigns the slave unit identification information to the slave unit 2.

  The slave unit identification information is information necessary for the master unit 1 to identify and communicate with each slave unit 2, while the measurement identification information is used by the host management device 6 for power billing. It is used for associating the measuring device 4 with the customer. The measurement identification information is set as information unique to each power measuring device 4 by combining the year of manufacture, the type of the power measuring device 4, the manufacturing number assigned to the power measuring device 4, and the like.

  Although only one master unit 1 is provided in the illustrated example, a plurality of (up to three) master units 1 can be provided. If three master devices 1 capable of managing 180 slave devices 2 are provided, 540 slave devices 2 can be managed. When a plurality of master units 1 are provided, each master unit 1 operates based on each setting. However, one master unit 1 functions as a master and other master units 1 operate in cooperation with the master. A configuration may be adopted.

  In order to identify the power supply management device 10 installed in the consumer by the parent device 1, the child device identification information for identifying the child device 2 is used. On the other hand, in order for the upper management device 6 to identify the power measurement device 4, measurement identification information individually assigned to each power measurement device 4 is used. By assigning the measurement identification information to each power measurement device 4, it is possible to manage the attachment / detachment of the power measurement device 4 with respect to the power supply management device 10.

  As described above, the slave unit identification information is used to identify the slave unit 2 under the management of the master unit 1, and the power measurement device 4 managed by the master unit 1 is identified under the management of the upper management device 6. Therefore, measurement identification information is used. Therefore, when the parent device 1 performs polling to acquire measurement data from the child device 2, the measurement identification information is used together with the child device identification information. The slave unit identification information and the measurement identification information are used for both an acquisition request from the master unit 1 to the slave unit 2 and a response from the slave unit 2 to the master unit 1. Although the host management device 6 acquires the slave unit identification information, the host management device 6 acquires measurement data from the power measurement device 4 and is not used as information.

  Hereinafter, the operation in which the parent device 1 acquires measurement data from each child device 2 is referred to as “regular meter reading”. The period of regular meter reading is defined as shown in Table 1, for example, according to the number of master units 1. Regular meter reading is performed in the data acquisition means 11 (see FIG. 1) provided in the main unit 1, and the period of regular meter reading is fixedly set in the data acquisition means 11 at the time of construction.

  In Table 1, the regular meter reading cycle becomes longer as the number of master units 1 increases. As the number of master units 1 increases, the number of slave units 2 to be managed increases. This is because the time required for communication becomes long, and the period of regular meter reading is the time required to perform other processing after making a measurement data acquisition request once for all the slave units 2. It has been decided to leave.

  On the other hand, the maximum time that one slave unit 2 can occupy for communication with the master unit 1 in regular meter reading is defined as “slot interval” as shown in Table 2. The slot interval is set in the slot control means 12 (see FIG. 1) provided in the base unit 1. The subunit | mobile_unit 2 respond | corresponds to multihop communication, and as shown in Table 2, the slot space | interval changes not only with the number of the main | base stations 1 but with "the number of hops". The number of hops corresponds to the number of slave units 2 that relay a message between the target slave unit 2 and the master unit 1 (actually, the number of routes between the slave units 2 or between the master unit 1 and the slave unit 2). .

  The slot interval is set so as to increase as the number of base units 1 increases and the maximum number of hops increases. Therefore, as the number of parent devices 1 increases, the traffic to one parent device 1 is reduced, and an increase in traffic (communication amount) per unit time in the entire system can be suppressed. The numerical values in Tables 1 and 2 are shown as examples, and these numerical values are desirable values, but can be changed as appropriate.

  By setting the slot interval in the relationship as described above, it is possible to equalize the time of each slave unit 2 when the master unit 1 makes a measurement data acquisition request to each slave unit 2. In other words, when the master unit 1 acquires measurement data from the slave unit 2, the slot interval is defined in consideration of the transmission time from the slave unit 2 that has the largest number of hops and requires a long communication time. Occurrence is suppressed.

As a condition for defining the slot interval, in addition to the maximum number of hops in one power line Lb, an average value of the number of hops can be used. Using the average value increases the probability of congestion compared to using the maximum number of hops, but while reducing the frequency of congestion, set the slot interval relatively short and measure against the regular meter reading cycle. It becomes possible to take much surplus time other than the time used for data acquisition.
It is possible to do.

  Furthermore, when the slot interval is set in association with the number of hops, the slot interval may be set variably according to the number of hops for each slave unit 2. In this case, the slot control means 12 of the master unit 1 defines the slot interval for each slave unit 2, and the processing becomes somewhat complicated to adjust the slot interval for each slave unit 2, but the congestion While avoiding the occurrence, it is possible to accurately manage the bandwidth usage rate of the transmission path between the parent device 1 and the child device 2.

  Now, the measurement data can be acquired from 180 slave units 2 with one master unit 1, and there is one master unit 1 and one set of slave units 2, each with 5 hops. In the case of 36 systems, if the data acquisition means 11 uses the values in Table 1 and the slot control means 12 uses the values in Table 2, the master unit 1 acquires measurement data from all the slave units 2. The time required for 10 seconds × 180 units = 30 minutes, and 18 minutes out of 48 minutes is the surplus time. On the other hand, if three master units 1 are used, measurement data can be acquired from a maximum of 540 slave units 2, but each master unit 1 manages a maximum of 180 slave units 2. The time required for the master unit 1 to acquire measurement data from all the slave units 2 is 24 seconds × 180 units = 72 minutes, and 18 minutes out of 90 minutes is the surplus time.

  In this embodiment, in the subunit | mobile_unit 2, the integrated electric power value (measurement data) of 0 minute and 30 minutes of every hour is calculated | required using the output of the electric power measurement apparatus 4. FIG. That is, 48 pieces of measurement data are passed to the base unit 1 per day. In addition, the slave unit 2 can hold the obtained measurement data for 40 days (1920), but a plurality (for example, three) each of the measurement data from the master unit 1 in response to one acquisition request. Measurement data is returned to the main unit 1.

  Therefore, when there is one master unit 1, as shown in FIG. 4, each slave unit 2 returns three pieces of measurement data to the master unit 1 at intervals of 48 minutes, which is the period of regular meter reading. (The shaded area represents the returned measurement data). In this case, although the master unit 1 receives one or two pieces of measurement data in duplicate for each regular meter reading, it can be said that the reliability of the measurement data increases because of the increased redundancy.

  On the other hand, when there are a plurality of master units 1 (two or three in this embodiment), each master unit 1 is spaced at intervals of 72 minutes or 90 minutes, as shown in FIGS. Therefore, three pieces of measurement data are acquired. That is, if there are two master units 1, each slave unit 2 passes three pieces of measurement data every 72 minutes to any one of the master units 1, so that the master unit 1 duplicates one piece of measurement data. If there are three master units 1, each slave unit 2 passes three pieces of measurement data every 90 minutes to one of the master units 1, so that the master unit 1 receives the measurement data without duplication. become.

  When a plurality of master units 1 are used, congestion occurs when each master unit 1 starts regular meter reading at the same time. Therefore, the start time when each master unit 1 performs regular meter reading is shifted by several seconds. The occurrence of congestion can be suppressed by shifting the start time of regular meter reading in each base unit 1.

  The slot interval is set not only by the number of base units 1 and the number of hops, but also by the success or failure of communication during communication between the base unit 1 and the handset 2 provided under the control of the base unit 1. Good. For example, since the success rate of communication decreases in an environment where noise is generated, the bandwidth is widened by adding the noise to the band occupied by each slave unit 2 by increasing the slot interval when communication fails. It becomes possible to increase the success rate of communication. In addition, when the communication is successful, a slot interval shorter than that at the time of failure is adopted, so that the use efficiency of the band used for communication is increased. In other words, by adjusting the slot interval variably according to the success or failure of communication, it is possible to increase the success rate of communication during a period in which noise is occurring, and to increase the efficiency of using the band in an environment without noise.

  The measurement data acquired from the slave unit 2 by the master unit 1 as described above is obtained from the meter reading value notification means 13 (FIG. 1) provided in the master unit 1 after the master unit 1 circulates all the slave units 2 once. By reference), the superordinate management device 6 is notified of the surplus time within the regular meter reading cycle. As a result of this operation, the integrated power value measured every 30 minutes by each power measuring device 4 is notified from the parent device 1 to the upper management device 6 every three periods of regular meter reading.

  By the way, depending on the state of the transmission path when the master unit 1 makes a request for acquisition of measurement data to the slave unit 2, a transmission error occurs even though the slave unit 2 acquires the measurement data. 1 may not be able to acquire measurement data. In such a case, if one or two master units 1 are used, measurement data may be obtained using the above-described redundancy, but measurement data can be obtained using the redundancy. When there is no data, the measurement data is not retransmitted between the parent device 1 and the child device 2.

  On the other hand, when the measurement data is missing in the host management device 6, the backup meter-reading means 6a (see FIG. 1) individually acquires the measurement data through the master unit 1 for the slave unit 2 in which the measurement data is missing. Try. Here, when normal measurement data is held in the slave unit 2, the measurement data can be notified to the upper management device 6, and the measurement data missing in the upper management device 6 can be supplemented. Can do.

  The backup meter-reading means 6a performs an operation of acquiring measurement data after confirming that the parent device 1 can communicate with the child device 2 in the surplus time in the regular meter-reading cycle. In general, when the master unit 1 fails to receive measurement data from the slave unit 2, it is considered that noise exists and the environment of the communication path is temporarily deteriorated. May fail to receive the measurement data again. On the other hand, since the backup meter-reading means 6a acquires measurement data after confirming that communication is possible, there is a high possibility that measurement data from the slave unit can be acquired.

  FIG. 7 shows a communication procedure for regular meter reading. In the regular meter reading, the master unit 1 makes a request for acquiring measurement data to each slave unit 2 (P1), and each slave unit 2 returns the measurement data to the master unit 1 (P2). The master unit 1 stores the acquired measurement data (P3), makes a measurement data acquisition request for all the slave units 2, and notifies the upper management device 6 of the end of regular meter reading (P4). This notification is performed as the occurrence of an event, and when the host management apparatus 6 receives the completion of reception of the measurement data as the occurrence of the event, it sends a reception confirmation response to the parent device 1 (P5). Thereafter, the upper management apparatus 6 acquires the measurement data stored in the parent device 1 by FTP (File Transfer Protocol) (P6).

  Here, when there is a gap in the acquired measurement data, the backup meter reading means 6a (see FIG. 1) of the upper management device 6 operates during the surplus time in the regular meter reading cycle, and attempts to acquire the measurement data. However, if there is an instruction from the upper management device 6 during the regular meter reading, the instruction has priority over the backup meter reading.

  FIG. 8 shows an operation procedure of the backup meter-reading means 6a. When the backup meter-reading means 6a operates, an individual operation request is made to the master unit 1 that manages the slave unit 2 in which the measurement data is missing so as to individually acquire the measurement data from the slave unit 2 ( P11). When the master unit 1 receives the individual operation request, it requests the slave unit 2 to acquire measurement data (P12). When normal measurement data is stored in the slave unit 2, the measurement data is stored in the master unit 1. Notification is made (P13). When the master device 1 acquires the measurement data from the slave device 2, it transfers it to the upper management device 6 (P14). When the measurement data is acquired from the slave unit 2 by the operation of the backup meter-reading means 6a, four pieces of measurement data (for two hours) are notified. Since the measurement data is associated with the measured time, the connection with other measurement data can be confirmed by acquiring four pieces of measurement data.

  The above operation is a single routine meter reading operation, and by repeating the same operation, the host management device 6 can collect meter reading data every 30 minutes.

  By the way, it is not only a communication error between the parent device 1 and the child device 2 that causes the measurement data to be lost in the upper management apparatus 6 but also due to an abnormality in the child device 2. Therefore, flags corresponding to various events occurring in the slave unit 2 can be set in the slave unit 2, and the event notification means 21 provided in the slave unit 2 can notify the master unit 1 of this flag as event information. . The event information is added to the measurement data and notified when there is a measurement data acquisition request from the parent device 1.

  That is, as shown in FIG. 9, the slave unit 2 stores a set of measurement data Dm, time Tm, and event information flag Fi, and in response to a measurement data acquisition request from the master unit 1, measurement is performed. The event information flag Fi is also notified to the parent device 1 together with the data Dm and the date and time Tm. The event information flag Fi is assigned to the date and time Tm associated with the measurement data Dm, corresponding to the events that have occurred in the past 30 minutes. Thus, event information is managed every 30 minutes.

  Events include, for example, replacement of the power measuring device 4, switching on / off state of the switchgear 9, power recovery from a power failure, time shift of the slave clock means 22 (see FIG. 1) for displaying the time on the slave unit 2. is there. The replacement of the power measuring device 4 is necessary to maintain the continuity of the measurement data at the time of replacement because the power measuring device 4 can be attached to and detached from the power supply management device 10. The status and power recovery information are necessary for grasping whether or not power is supplied to each consumer. The time shift of the sub clock means 22 will be described later.

  Since the event notification means 21 is provided in the child device 2 and is added to the measurement data notified to the parent device 1 to notify the event information, when the event occurs in the child device 2 or the power measuring device 4, the parent device 1 Then, the event information can be grasped, and the event information can be grasped by the upper management apparatus 6 as necessary. If the backup meter reading means 6a is used, even if the event information from the child device 2 has not reached the parent device 1, the event information can be acquired by the upper management device 6.

  By the way, since the measurement data obtains the integrated power value at intervals of 30 minutes between 0 minutes and 30 minutes, it is necessary to manage the time. The parent device 1 can accurately manage the time using an NTP (Network Time Protocol) server, but the child device 2 can manage the time only through the parent device 1. Therefore, as shown in FIG. 1, the parent device 1 uses the NTP server to measure the reference date and time, and the date and time when the parent device 1 notifies the child device 2 of the date and time measured by the parent clock device 14. The slave unit 2 includes a slave clock unit 22 that counts the date and time, the date and time counted by the master clock unit 14 received from the master unit 1, and the slave clock unit 22 clocks the slave unit 2. The date and time correcting means 23 is provided for comparing the date and time counted by the slave clock means 22 with the date and time counted by the parent clock means 14 by comparing with the date and time being counted.

  The date and time notification means 15 adds the date and time measured by the parent clock means 14 when the parent device 1 makes a request for acquiring measurement data to each child device 2. In other words, since the slave device 2 is notified of the reference date and time together with the measurement data acquisition request, it is not necessary to perform separate communication for time adjustment, thereby suppressing an increase in traffic. Further, since the master unit 1 periodically notifies the slave unit 2 of the date and time counted by the master clock means 14, it is possible to suppress the occurrence of time lag in the slave unit 2, and The reliability of the date and time being measured by the clock means 22 is improved.

  By the way, in this embodiment, since multihop communication is performed as described above, the delay time until information arrives between the parent device 1 and the child device 2 differs depending on the child device 2. Therefore, the master unit 1 estimates the delay time until the measurement data acquisition request reaches the slave unit 2 (estimated by the number of hops or turnaround time) and the date / time notification unit 15. There is provided a date and time adjusting means 17 for adjusting the date and time notified to the slave unit 2 by the delay time estimated by the delay time estimating means 16.

  For example, if the delay time from the base unit 1 to the handset 2 estimated by the delay time estimation unit 16 is 1 second, the date and time adjustment unit 17 sets 1 to the date and time counted by the master clock unit 14. The value advanced by seconds is transmitted to the corresponding slave unit 2. Since the slave unit 2 receives the date and time value after one second, the reception time and the date and time counted by the master clock unit 14 coincide with each other, and the date and time correction unit 23 adds the date and time of the slave clock unit 22 to this date and time. Can be made to coincide with the date and time measured by the parent clock means 14 and the date and time measured by the child clock means 22.

  By the way, if any abnormality occurs in the slave unit 2 (for example, the capacity of the backup battery that supplies power so that the slave clock unit 22 does not stop when a power failure occurs), the date and time counted by the slave clock unit 22 is The date and time measured by the means 14 may be significantly different. Since base unit 1 uses the NTP server to perform time adjustment, an abnormality in base unit 1 is detected in base unit 1. On the other hand, when a time lag has occurred in the slave clock means 22 due to an abnormality in the slave unit 2, it is detected by the slave unit processing means 20 provided in the slave unit 2 when the date correction unit 23 compares the date and time.

  The slave unit processing means 20 is a means for managing the operation of the slave unit 2, stores the above-described measurement data and event information flags, and returns the measurement data in response to an acquisition request from the data acquisition unit 11. Processing is also performed. In the slave unit processing means 20, when the date and time correction means 23 compares the date and time measured by the master clock means 14 received from the master unit 1 and the date and time measured by the slave clock means 22, the time difference is calculated. When a specified time (for example, 5 minutes) is exceeded, the operation of the child device 2 is stopped. As a result, it is possible to prevent the electricity bill from being charged based on erroneous measurement data when there is a significant time lag in the date and time being counted by the slave unit 2.

  In the above example, the operation of the slave unit 2 is stopped when the time difference between the date and time measured by the master clock means 14 and the date and time measured by the slave clock means 22 exceeds a specified time. The information to be shown may be notified to the main unit 1 together with the measurement data. The measurement data in this case is handled as reference information.

  In the above operation example, the slave unit 2 determines the time lag between the master clock unit 14 and the slave clock unit 22, but the date and time added to the measurement data acquired from the slave unit 2 in the master unit 1. When the time difference exceeds a specified time (for example, 5 minutes), the measurement data of the slave unit 2 is not adopted and the slave unit 2 is not used. You may make it treat it as removal.

It is a block diagram of the principal part same as the above. It is a block diagram which shows the system configuration | structure of embodiment. The power supply management apparatus used for the above is shown, (a) is a front view, and (b) is a side view. It is operation | movement explanatory drawing of the regular meter-reading by the one main | base station in the same as the above. It is operation | movement explanatory drawing of the regular meter-reading by the two main | base stations in the same as the above. It is operation | movement explanatory drawing of the regular meter-reading by the three main | base stations in the same as the above. The operation | movement explanatory drawing which shows the procedure of regular meter-reading in the same as the above can be obtained. It is operation | movement explanatory drawing which shows the procedure of the backup meter-reading in the same as the above. It is a figure which shows the structural example of the data which a subunit | mobile_unit memorize | stores in the same as the above. It is a block diagram which shows the conventional system configuration.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Master machine 2 Slave machine 4 Power measuring device 6 High-order management apparatus 6a Backup meter-reading means 11 Data acquisition means 12 Slot control means 13 Meter-reading value notification means 14 Parent clock means 15 Date-time notification means 16 Delay time estimation means 17 Date-time adjustment means 20 Child Machine processing means 21 Event notification means 22 Slave clock means 23 Date and time correction means NT Wide area information communication network

Claims (14)

  Communication by power line carrier communication through a communication path including a power line between a plurality of slave units that are provided for each power measurement device that measures power used by consumers and that respectively acquires measurement data by the power measurement device. A master unit that acquires measurement data from the slave unit, and a higher-level management device that collects measurement data acquired by the master unit by communicating with the master unit through a communication path including a wide area information communication network The master unit has a data acquisition means for periodically acquiring and acquiring measurement data from each slave unit at a slot interval that is a specified time, and a meter reading for notifying the host management device of the measurement data acquired from the slave unit A remote meter-reading system comprising: a value notification means; and a slot control means for variably determining a slot interval according to a communication condition with a slave unit.   The slave unit is capable of multi-hop communication, and the slot control means defines a slot interval in association with the maximum number of hops in the slave unit provided under the management of the master unit. The remote meter reading system according to claim 1.   The slave unit is capable of multi-hop communication, and the slot control means defines a slot interval in association with an average value of the number of hops in the slave unit provided under the management of the master unit. The remote meter reading system according to claim 1.   The slave unit is capable of multi-hop communication, and the slot control means defines a slot interval in association with the number of individual hops in the slave unit provided under the management of the master unit. The remote meter reading system according to claim 1.   The slot control means defines a slot interval according to the success or failure of communication during communication with the child device provided under the management of the parent device, and uses a shorter slot interval than when the communication fails when the communication is successful. The remote meter reading system according to claim 1.   6. The device according to claim 1, wherein a plurality of the parent devices are provided, and the slot control unit sets a longer slot interval between the parent devices as the number of parent devices increases. 6. Remote meter reading system.   2. The master device according to claim 1, wherein a plurality of master devices are provided, and the slot control means sets different start times when each master device circulates and acquires measurement data from the slave devices under management. The remote meter-reading system of any one of -6.   When the master unit has failed to acquire measurement data from the slave unit, the host management device transmits the measurement data of the slave unit to the master unit after the master unit becomes communicable with the slave unit. The remote meter reading system according to any one of claims 1 to 7, further comprising backup meter-reading means for individually acquiring through the meter.   The master unit has a master clock unit for timing a reference date and time, and a date / time notification unit for notifying the slave unit of the date and time that the master clock unit counts when making a measurement data acquisition request to the slave unit. The slave unit includes: a slave clock unit that counts the date and time; and a date correction unit that adjusts the date and time counted by the slave clock unit to the date and time counted by the master clock unit received from the master unit. The remote meter-reading system of any one of 1-8.   The master unit includes a master clock unit that counts a reference date and time, and a notification unit that periodically notifies the slave unit of the date and time that the master clock unit counts, and the slave unit counts the date and time. 9. The method according to claim 1, further comprising: a sub-clock unit that performs time adjustment, and a date and time correction unit that adjusts the date and time counted by the sub-clock unit to the date and time counted by the parent clock unit received from the base unit. The remote meter reading system described.   The slave unit includes a slave unit processing unit that stops the operation of the slave unit when a time difference between a date and time counted by the master clock unit and a date and time counted by the slave clock unit exceeds a specified time. The remote meter-reading system according to claim 9 or 10.   The slave unit is configured to add time shift information to measurement data of the slave unit when a time difference between the date and time measured by the master clock unit and the date and time measured by the slave clock unit exceeds a specified time. The remote meter reading system according to claim 9 or 10, further comprising: means.   The master unit is a delay time estimation unit that estimates a delay time until a measurement data acquisition request reaches the slave unit, and a delay time that is estimated by the delay time estimation unit. The remote meter reading system according to any one of claims 1 to 12, further comprising a date and time adjustment unit that adjusts the time.   The said subunit | mobile_unit is provided with the event notification means which adds event information which shows generation | occurrence | production of an event to measurement data, when an event arises in at least one of the said electric power measurement apparatus and a subunit | mobile_unit. The remote meter reading system according to any one of the above.

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